/*
 *	aegis - project change supervisor
 *	Copyright (C) 2001 Peter Miller;
 *	All rights reserved.
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: functions to manipulate catenates
 */

#include <ac/string.h>

#include <mem.h>
#include <str.h>


/*
 * NAME
 *	str_catenate - join two strings
 *
 * SYNOPSIS
 *	string_ty *str_catenate(string_ty *, string_ty *);
 *
 * DESCRIPTION
 *	The str_catenate function is used to concatenate two strings to form a
 *	new string.
 *
 * RETURNS
 *	string_ty* - a pointer to a string in dynamic memory.  Use str_free when
 *	finished with.
 *
 * CAVEAT
 *	The contents of the structure pointed to MUST NOT be altered.
 */

string_ty *
str_catenate(s1, s2)
	string_ty	*s1;
	string_ty	*s2;
{
	static char	*tmp;
	static size_t	tmplen;
	string_ty	*s;
	size_t		length;

	length = s1->str_length + s2->str_length;
	if (!tmp)
	{
		tmplen = length;
		if (tmplen < 16)
			tmplen = 16;
		tmp = mem_alloc(tmplen);
	}
	else
	{
		if (tmplen < length)
		{
			tmplen = length;
			tmp = mem_change_size(tmp, tmplen);
		}
	}
	memcpy(tmp, s1->str_text, s1->str_length);
	memcpy(tmp + s1->str_length, s2->str_text, s2->str_length);
	s = str_n_from_c(tmp, length);
	return s;
}